The present invention relates to an image display control device and the like. More particularly, the invention relates to an image display control device which acquires statistical information of an input image and adaptively corrects the image based on the acquired statistical information, and the like.
JP-A-2004-200904 and JP-A-2005-108194 disclose technology which corrects a still image based on a statistical value of the still image.
JP-A-11-65531 discloses technology which reduces the quantity of light emitted from a backlight aimed at reducing power consumption, and adjusts image data to increase the transmissivity of a liquid crystal display screen as much as possible.
JP-A-2004-310671 discloses an image correction device which uses a look-up table (LUT) in order to correct a luminance signal of a display image.
In order to adaptively correct a video image based on a statistical value, it is necessary to efficiently and quickly acquire the statistical value of the video image.
In particular, in order to simultaneously perform a reduction in luminance of lighting (e.g., backlight) and adaptive video image correction aimed at preventing deterioration in image quality, it is necessary to perform a large number of calculations based on various acquired statistical values. Therefore, it is indispensable to efficiently and quickly acquire various statistical values used for calculations.
For example, in order to appropriately correct a video image, it may be necessary to acquire the statistical value relating to the chroma (color difference) of the input video image in real time in addition to the statistical value relating to the luminance. It may also be necessary to acquire the average value of the luminance, the average value of the chroma (color difference), and the like in real time in addition to the maximum value, the minimum value, and the standard deviation value of the luminance. In such a case, the statistical value acquisition operation and the circuit configuration of a statistical information acquisition section (histogram creation section) become more and more complicated.
Calculations performed when simultaneously performing a reduction in luminance and image correction may be simplified by utilizing a look-up table (LUT) which stores calculation results. However, memory access takes time. Therefore, a method using an LUT is not suitable when a real-time capability is required, such as when reproducing a streaming image distributed by one-segment broadcasting (digital broadcasting for portable telephone terminals) using a portable telephone terminal.
A high-speed capability (real-time capability) can be ensured by causing a plurality of pieces of dedicated hardware to perform specific calculations in parallel. However, the occupied area and the power consumption of the circuit are inevitably increased.
As described above, in order to perform adaptive real-time video image correction (in particular, simultaneously perform a reduction in lighting luminance and image correction which compensates for deterioration in image quality due to a reduction in luminance), a real-time capability is required for acquisition of the statistical information and calculations using the statistical information. Moreover, suppression of an increase in circuit scale and a reduction in power consumption are also required. Related-art technologies cannot deal with such requirements.